A vulnerability in SIEMENS SIMATIC WinCC (All versions < SIMATIC WinCC V7.2) and SIEMENS SIMATIC PCS 7 (All versions < SIMATIC PCS 7 V8.0 SP1) could allow a remote attacker to crash an ActiveX component or leak parts of the application memory if a user is tricked into clicking on a malicious link under certain conditions.
https://ics-cert.us-cert.gov/advisories/ICSA-16-348-04
http://www.siemens.com/cert/pool/cert/siemens_security_advisory_ssa-693129.pdf